1 Quick Instructions

First, throw away ".zo" versions of your program—at least for the modules or files that should be instrumented for error reporting or profiling.

Then,

• If your program has a module file ‹prog›, run it with

    racket -l errortrace -t ‹prog›

• If you program is a non-module top-level sequence of definitions and expressions, you can instead add

  (require errortrace)

  to the beginning of the program or start Racket with the -l option before the arguments to load your program:
    racket -l errortrace ...

• If you have no main program and you want to use Racket interactively, include the -i flag before -l:
    racket -i -l errortrace

• To instrument the contents of a collection or package, compile it with:
    raco setup --mode errortrace ...

After starting errortrace in one of these ways, when an exception occurs, the exception handler prints something like a stack trace with most recent contexts first.

The errortrace module is strange: Don’t import it into another module. Instead, the errortrace module is meant to be invoked from the top-level, so that it can install an evaluation handler, exception handler, etc.

To reuse parts of the code of errortrace, import errortrace/errortrace-lib. That library contains all of the bindings described here, but does not set the compilation handler or the error display handler.